unprecedented [Adjective] + challenge [Noun]

Strength Strength Dispersion
A:
4
CHISQ:
7.22
AWT:
21,436,106
TTEST:
1.43
G2:
7.08
FAWT:
2.54
MI:
1.81
LOGLOG:
3.63
JD:
0.51
MI3:
5.81
DICE:
0.11
RANGE: